问题描述
我有一个核心数据Swift主/详细视图应用程序（代码位于here），其中的核心数据对象称为sweetnote，基本上是这样的：
class sweetnote: NSObject {
private(set) var noteId : UUID
private(set) var noteTitle : String
private(set) var noteText : NSAttributedString
private(set) var noteCreated : Int64
private(set) var noteModified : Int64
private(set) var noteCategory : String
}
我有一个Master视图控制器，该控件借助Helpers / sweetnoteCoreDataHelper.swift中名为readNotesFromCoreData的函数在UITableView中呈现这些注释：
static func readNotesFromCoreData(fromManagedobjectContext: NSManagedobjectContext) -> [sweetnote] {
var returnednotes = [sweetnote]()
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Note")
fetchRequest.predicate = nil
do {
let fetchednotesFromCoreData = try fromManagedobjectContext.fetch(fetchRequest)
fetchednotesFromCoreData.forEach { (fetchRequestResult) in
let noteManagedobjectRead = fetchRequestResult as! NSManagedobject
returnednotes.append(sweetnote.init(
noteId: noteManagedobjectRead.value(forKey: "noteId") as! UUID,noteTitle: noteManagedobjectRead.value(forKey: "noteTitle") as! String,noteText: noteManagedobjectRead.value(forKey: "noteText") as! NSAttributedString,noteCreated: noteManagedobjectRead.value(forKey: "noteCreated") as! Int64,noteModified: noteManagedobjectRead.value(forKey: "noteModified") as! Int64,noteCategory: noteManagedobjectRead.value(forKey: "noteCategory")
as! String))
}
} catch let error as NSError {
// Todo error handling
print("Could not read notes from core data. \(error),\(error.userInfo)")
}
// Set note count
self.count = returnednotes.count
// Sort by modified date
return returnednotes.sorted() {
$0.noteModified > $1.noteModified
}
}
然后在主视图控制器（位于UI / MasterViewController.swift中）中，我在UITableView的顶部配置了一个UISearchController，该控件当前未基于文本应用任何过滤逻辑，并且我无法确定在哪里需要更新：
import UIKit
import Foundation
import CoreData
class MasterViewController: UITableViewController,NSFetchedResultsControllerDelegate,UISearchBarDelegate,UISearchResultsUpdating {
var detailViewController: DetailViewController? = nil
var searchtemplate: String? {didSet {print (searchtemplate as Any)}}
// Search results controller
let resultSearchController = UISearchController(searchResultsController: nil)
var sweetnotes: [sweetnote] = []
var searchResults: [sweetnote] = []
override func viewDidLoad() {
super.viewDidLoad()
// Core data initialization
guard let appDelegate = UIApplication.shared.delegate as? AppDelegate else {
// Create alert controller
let alert = UIAlertController(
title: "Could note get app delegate",message: "Could note get app delegate,unexpected error occurred. Try again later.",preferredStyle: .alert)
// Add OK action
alert.addAction(UIAlertAction(title: "OK",style: .default))
// Show alert
self.present(alert,animated: true)
return
}
// Pass the context forward from the app delegate
let managedContext = appDelegate.persistentContainer.viewContext
// Set context in the storage
sweetnoteStorage.storage.setManagedContext(managedobjectContext: managedContext)
// Set the search controller programmatically
resultSearchController.searchResultsUpdater = self
resultSearchController.hidesNavigationBarDuringPresentation = false
resultSearchController.obscuresBackgroundDuringPresentation = false
self.definesPresentationContext = true
// Scope bar
//resultSearchController.searchBar.scopeButtonTitles = ["All","Ideas","information","Lifestyle","Lists","Recipes","Other"]
//searchView.addSubview(resultSearchController.searchBar)
tableView.tableHeaderView = resultSearchController.searchBar
resultSearchController.searchBar.tintColor = UIColor.darkGray
resultSearchController.searchBar.barTintColor = UIColor(red: 0.9,green: 0.9,blue: 0.9,alpha: 0.8)
resultSearchController.searchBar.placeholder = "Search sweetnotes"
// Prefer large titles
self.navigationController?.navigationBar.prefersLargeTitles = true
// Edit-note button
navigationItem.leftBarButtonItem = editButtonItem
// Add-note button
let addButton = UIBarButtonItem(barButtonSystemItem: .add,target: self,action: #selector(insertNewObject(_:)))
navigationItem.rightBarButtonItem = addButton
if let split = splitViewController {
let controllers = split.viewControllers
detailViewController = (controllers[controllers.count-1] as! UINavigationController).topViewController as? DetailViewController
}
self.tableView.delegate = self
}
...
override func viewWillAppear(_ animated: Bool) {
cleaRSSelectionOnViewWillAppear = splitViewController!.isCollapsed
super.viewWillAppear(animated)
}
// dismiss search bar on scroll-down
override func viewWilldisappear(_ animated: Bool) {
super.viewWilldisappear(animated)
resultSearchController.dismiss(animated: false,completion: nil)
}
@objc
func insertNewObject(_ sender: Any) {
performSegue(withIdentifier: "showCreateNoteSegue",sender: self)
}
// MARK: - Segues
override func prepare(for segue: UIStoryboardSegue,sender: Any?) {
if segue.identifier == "showDetail" {
if let indexPath = tableView.indexPathForSelectedRow {
//let object = objects[indexPath.row]
let object = sweetnoteStorage.storage.readNote(at: indexPath.row)
let controller = (segue.destination as! UINavigationController).topViewController as! DetailViewController
controller.detailItem = object
controller.navigationItem.leftBarButtonItem = splitViewController?.displayModeButtonItem
controller.navigationItem.leftItemsSupplementBackButton = true
//controller.detailItem = resultSearchController.isActive ? searchResults[indexPath.row] : sweetnotes[indexPath.row]
}
}
}
// MARK: - Table View
func searchBar(_ searchBar: UISearchBar,selectedScopeButtonIndexDidChange selectedScope: Int) {
filterContentForSearchText(searchBar.text!,scope: searchBar.scopeButtonTitles![selectedScope])
}
func updateSearchResults(for searchController: UISearchController) {
guard let text = searchController.searchBar.text else { return }
print(text)
}
func filterContentForSearchText(_ searchText: String,scope: String = "All") {
searchtemplate = searchText
tableView.reloadData()
}
func updateSearchResultsForSearchController(searchController: UISearchController,fromManagedobjectContext: NSManagedobjectContext) {
let searchText = searchController.searchBar.text!
let predicate = nspredicate(format: "%K CONTAINS[c] %@",argumentArray: ["noteText",searchText])
let fetchRequest = NSFetchRequest<NSFetchRequestResult>(entityName: "Note")
fetchRequest.predicate = predicate
do {
let fetchednotesFromCoreData = try fromManagedobjectContext.fetch(fetchRequest)
fetchednotesFromCoreData.forEach { (fetchRequestResult) in
let noteManagedobjectRead = fetchRequestResult as! NSManagedobject
searchResults.append(sweetnote.init(
noteId: noteManagedobjectRead.value(forKey: "noteId") as! UUID,\(error.userInfo)")
}
tableView.reloadData()
}
...
override func tableView(_ tableView: UITableView,numberOfRowsInSection section: Int) -> Int {
if resultSearchController.isActive && resultSearchController.searchBar.text != "" {
return searchResults.count
} else {
return sweetnoteStorage.storage.count()
}
}
override func tableView(_ tableView: UITableView,cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell",for: indexPath) as! sweetnoteUITableViewCell
//let note = fetchedResultsController.object(at: indexPath)
//configureCell(cell,withEvent: note)
if let object = sweetnoteStorage.storage.readNote(at: indexPath.row) {
cell.noteTitleLabel!.text = object.noteTitle
cell.noteTextLabel!.attributedText = object.noteText
cell.noteCategoryLabel!.text = object.noteCategory
cell.noteDateLabel!.text = sweetnoteDateHelper.convertDate(date: Date.init(minutes: object.noteModified))
}
//cell.contentView.layer.cornerRadius = 6.0
//cell.contentView.layer.borderColor = UIColor.gray.withAlphaComponent(0.5).cgColor
//cell.contentView.layer.borderWidth = 1.0
//cell.contentView.layer.masksToBounds = true
//cell.contentView.clipsToBounds = true
cell.backgroundColor = UIColor.white
cell.selectionStyle = UITableViewCell.SelectionStyle.none
return cell
}
override func tableView(_ tableView: UITableView,canEditRowAt indexPath: IndexPath) -> Bool {
// Return false if you do not want the specified item to be editable
if resultSearchController.isActive {
return false
} else {
return true
}
}
override func tableView(_ tableView: UITableView,commit editingStyle: UITableViewCell.EditingStyle,forRowAt indexPath: IndexPath) {
if editingStyle == .delete {
presentDeletionFailsafe(indexPath: indexPath)
//objects.remove(at: indexPath.row)
//sweetnoteStorage.storage.removeNote(at: indexPath.row)
//tableView.deleteRows(at: [indexPath],with: .fade)
} else if editingStyle == .insert {
// Create a new instance of the appropriate class,insert it into the array,and add a new row to the table view.
}
}
// Deletion failsafe function
func presentDeletionFailsafe(indexPath: IndexPath) {
let alert = UIAlertController(title: nil,message: "Are you sure you would like to delete this note?",preferredStyle: .alert)
// Delete the note
let yesAction = UIAlertAction(title: "Yes",style: .default) { _ in
// replace data variable with your own data array
sweetnoteStorage.storage.removeNote(at: indexPath.row)
self.tableView.deleteRows(at: [indexPath],with: .fade)
}
alert.addAction(yesAction)
// Cancel and don't delete note
alert.addAction(UIAlertAction(title: "Cancel",style: .cancel,handler: nil))
present(alert,animated: true,completion: nil)
}
func configureCell(_ cell: sweetnoteUITableViewCell,withEvent note: Note) {
cell.noteTitleLabel!.text = note.noteTitle
cell.noteTextLabel!.attributedText = note.noteText
cell.noteCategoryLabel!.text = note.noteCategory
cell.noteDateLabel!.text = sweetnoteDateHelper.convertDate(date: Date.init(minutes: note.noteModified))
}
}
函数updateSearchResultsForSearchController是我尝试建立谓词并执行搜索结果获取请求的地方，基于那里的一些类似问题，人们在核心数据项目之上实现了搜索控制器，但我肯定仍然缺少某些东西因为将文字输入搜索栏时，所有注释仍保留在表格视图中。
由于我在此上花了很多时间，所以任何答案/建议都将受到高度赞赏。如果可以帮助您，我很乐意提供更多信息和上下文。同样，代码位于项目here的“ searchbar”分支中。预先非常感谢。
解决方法
暂无找到可以解决该程序问题的有效方法，小编努力寻找整理中！
如果你已经找到好的解决方法，欢迎将解决方案带上本链接一起发送给小编。
小编邮箱:dio#foxmail.com (将#修改为@）